Volvo Penta 2.1 2.3 Automotive Water Pump Circulation Pump AQ125

[clay37355]

Hello Folks. First time post. I recently purchased a 84 Bayliner Capri. It has the Volvo Penta 2.1L AQ125. The water pump was out in it. The circulation pump not the fresh/salt water pump. I check the price of a new water pump and they were all $300 +. I couldnt do this. I did some research and found that the marine aq125 and the automotive 2.1 and 2.3 engines were alot alike. I found out the water pump for 1976 through 1984 2.1 and 2.3 Liter Volvo Cars Were close to the marine ones. I bought one and modified it to work on the aq125. The water pump through a Local part store was $32. I searched on iboats of a write up of someone using the automotive pump but couldn't find one. If this is a re post of someone doing the same thing ... sorry.. Im no engineer or machinist and im sure there are better methods out there. But i basically cut the tube the radiator hose slipped over on the automotive pump and put the connector for the heat separator on the automotive water pump. I also had to block off the small hole in the back of the automotive pump. Here is all i did.

These photos shows both pumps side by side


Here is the area of difference in the two pumps

 

[clay37355]

Re: Volvo Penta 2.1 2.3 Automotive Water Pump Circulation Pump AQ125

I measured the height of the inlet hole on the marine pump from the body to the tip



Then transfer that measurement to the automotive pump and marked where it was to be cut.



I cut the the tip off using a chop saw. A little crooked but that was all i had to cut it



I next had to enlarge the hole for the heat separator connector to fit inside the automotive water pump. All i had to do this with was a carbide cutter. I know I know this is redneck. A machine shop would have been a better choice to do this but im on an extreme budget.

 

[clay37355]

Re: Volvo Penta 2.1 2.3 Automotive Water Pump Circulation Pump AQ125

Here is the aftermath of the redneck hole enlargement. I kept grinding until the connector would barely fit inside. It never would slide in. I wanted it where i had to hammer it in.



After I was done cutting I blew the water pump out with compressed air to clean all the shavings. I took the connector and had to cut it down to make up for the overall length of the connector. Because its not sliding in and sealing inside the inlet of the water pump. To be honest I never tried to use the connector without cutting it and it may have slid up in the heat exchanger and been ok. I slide the plastic spacer over the connectors long side and marked it


Then cut at the outside edge of the mark, but leave the mark. I used the chop saw again to make the cut.



I Installed the rubber gasket then coated the shorter side of the connector with Grey RTV Silicone. I did the same to the inlet hole of the water pump

 

[clay37355]

Re: Volvo Penta 2.1 2.3 Automotive Water Pump Circulation Pump AQ125

Then I hammered the short side of the connector in the hole. Until the gasket compressed against the housing.



Now i had to move on the the extra hole in the back of the water pump next to the water inlet



Again.... Im sure there are better ways but here is what i cam up with, Cost me a little over $0.06 literally.



I first coated the inside edge of the penny with jb weld

 

[clay37355]

Re: Volvo Penta 2.1 2.3 Automotive Water Pump Circulation Pump AQ125

Then i pushed the penny inside the hole. With the JB weld to the inside.It fit almost perfectly with the jb weld sealing against the lip inside the water pump.



I then rolled the outer rim of the nickle in the JB weld and pushed it in the hole. Again a nice fit since the hole is tapered. I then took a ball peen hammer and tapped it in the hole. Then went around the edge with a sharp punch and staked it in place.



I installed the spacer and gasket. Here is the water pump ready to go in. And Installed.



I had to used 3 small nuts as spacers behind the heat separator tank on each of the 3 bolts when i bolted it on. I believe the connector sticks out a little too far doing it this way. If anyone else does this you may want to try to cut the pump inlet a little shorter and/or leave the gasket out when the connector is hammered in the water pump.
I ran it all day today without a leak. So far so good. I plan on running it again tomorrow all day and will post if any leaks pop up. Hope this helps save someone else some money.

 

[Nickypoo]

Re: Volvo Penta 2.1 2.3 Automotive Water Pump Circulation Pump AQ125

Hi clay, good job with the write-up and automotive pump install.

I saw a thread on here where someone tried to do exactly what you did. They found out that the outlet on the automotive pump didn't match up exactly with the inlet of the heat exchanger, so they never got it to work.

It's good you got it to work and I'm sure this will help someone on a budget, like many of us "do it yourselfers" are.

 

[at1oliver]

Re: Volvo Penta 2.1 2.3 Automotive Water Pump Circulation Pump AQ125

Nice job, I too may try your method.

 

[FatRabbit]

Wow..! I'm going thru the same situation right now and struggling to get things to line up. Thank you for sharing...!